Question

Possible Duplicate:
What is the correct way to create a single instance application?
How to implement single instance per machine application?

I have a Winform-app which takes one parameter as an argument.

static class Program
{

    [STAThread]
    static void Main(string[] args)
    {           
        Application.EnableVisualStyles();
        Application.SetCompatibleTextRenderingDefault(false);
        Application.Run(new Gauges(args));
    }
}

This program is executed by another application several times a day.

Is it possible to check if my programm is already running and if so, can I use the running instance with the latest parameter?

Answer 1

Is it possible to check if my programm is already running

You can use Mutex inside your application

bool alreadyPresent  =false;
using (Mutex mutex = new Mutex(true, "YourAppName", out alreadyPresent  ))
{
    if(alreadyPresent ) {
       //APP ALREADY PRESENT 
    }
}

Mutex is OS artifact, so, different instances of your application (executable) cann access the same object.

can I use the running instance with the latest parameter?

It depends how do you manage your app. You can use some IPC mechanism to communicate requeired parameter to already running process.